Do GLP-1 Weight-Loss Drugs Lower the Risk of Some Obesity-Related Cancers?

Medications known as GLP-1 receptor agonists, including semaglutide and tirzepatide, have changed the treatment of obesity and type 2 diabetes over the past few years. Beyond helping people lose weight, researchers have been investigating whether these medicines may also influence the long-term risk of developing certain cancers.

Two large observational studies have addressed this question directly.

What did the researchers study?

A study by Dai and colleagues, published in JAMA Oncology in August 2025, used electronic health records from a large research network in Florida covering 2014 to 2024. The investigators compared 43,317 adults with overweight or obesity who were prescribed GLP-1 receptor agonists with 43,315 similar adults who were not — 86,632 people in total. None had a previous cancer diagnosis at the start.

An earlier study by Wang and colleagues, published in JAMA Network Open in July 2024, looked at more than 1.6 million patients with type 2 diabetes and compared GLP-1 receptor agonists with insulin and with metformin.

What were the main findings?

In the JAMA Oncology study, cancer was diagnosed in 13.6 per 1,000 person-years among people taking GLP-1 medications, compared with 16.4 per 1,000 among non-users. That corresponds to an overall risk roughly 17% lower.

The association reached statistical significance for three cancers:

• endometrial cancer
• ovarian cancer
• meningioma

For most of the other cancers examined, the numbers pointed in the same direction but did not reach statistical significance.

The researchers also observed a possible increase in kidney cancer risk. This finding did not reach statistical significance and, in the authors' words, requires longer follow-up before any conclusion can be drawn.

In the earlier JAMA Network Open study, GLP-1 receptor agonists were associated with a lower risk of 10 of 13 obesity-associated cancers compared with insulin. Compared with metformin, no reduction in cancer risk was found. That distinction matters: the comparison drug shapes the result.

Does this mean GLP-1 drugs prevent cancer?

No.

These studies do not prove that GLP-1 medications prevent cancer. They show an association, not a cause-and-effect relationship.

There are several possible explanations:

• weight loss itself may reduce cancer risk
• improved blood sugar control could contribute
• lower levels of chronic inflammation may play a role
• other differences between the groups may have influenced the results

It is also worth noting that a meta-analysis published in late 2025, pooling data from randomised trials, found little or no overall link between GLP-1 receptor agonists and cancer incidence. Randomised trials and observational studies do not always point in the same direction, and this question is not settled.

Why obesity matters

Scientists have long known that obesity increases the risk of multiple cancers. Thirteen cancers are currently classified as obesity-associated.

Excess body fat is associated with chronic inflammation, hormonal changes, insulin resistance and other biological processes that may contribute to cancer development.

Reducing obesity is already known to improve overall health, regardless of the specific treatment used.

What should patients do?

These findings should not encourage anyone to start GLP-1 medication solely to reduce cancer risk.

These are prescription medicines that should only be used when recommended by a qualified healthcare professional, after evaluating the potential benefits, risks, side effects and individual medical history.

Study limitations

The authors highlighted several important limitations:

• these were observational studies, not randomised trials
• treatment was not randomly assigned, so the groups may differ in ways that were not measured
• follow-up was relatively short for assessing lifetime cancer risk
• cancers develop over many years, and the studies covered a shorter period
• more long-term research is required

Because of these limitations, the findings should be interpreted cautiously.

Bottom line

Large real-world studies suggest that GLP-1 receptor agonists may be associated with a lower overall risk of several obesity-related cancers.

However, the results do not prove that these medications prevent cancer, and randomised evidence so far has been less clear. More long-term research is needed before treatment recommendations change.

For now, GLP-1 medications remain approved for specific indications such as obesity management and type 2 diabetes — not for cancer prevention.

Medical disclaimer

This article is for educational purposes only and should not be considered medical advice. Decisions about medications or cancer prevention should always be made together with a qualified healthcare professional.

Sources

• Dai H, Li Y, Lee YA, et al. GLP-1 Receptor Agonists and Cancer Risk in Adults With Obesity. JAMA Oncol. 2025;11(10):1186–1193.
• Wang L, Xu R, Kaelber DC, Berger NA. Glucagon-Like Peptide 1 Receptor Agonists and 13 Obesity-Associated Cancers in Patients With Type 2 Diabetes. JAMA Netw Open. 2024;7(7):e2421305.